Welding apparatus



Jan. 25, 1949. T. w. GRIFFITHS WELDING APPARATUS Filed May 51, 1946 1NVENTOR.

T s s ATTORNEY Patented Jan. 25, 1949 WELDING APPARATUS Thomas W.Grifiiths, Newark, N. J., assignor to Federal Telephone and RadioCorporation, New York, N. Y., a corporation of Delaware Application May31, 1946, Serial No. 673,213

4 Claims.

This invention relates to a protecting cover to be placed over anarticle being welded and more particularly to a protecting cover, worksupport and light filter to be used in a welding operation where thewelding operation is carried out in an atmosphere of hydrogen.

The use of a protecting cover in the form of a bell jar is desirable inconnection with the welding of delicate parts of radio tubes. The radiotubes upon which this particular type of welding process and weldingequipment have been found most useful are high-powered tubes used mostlytransmitters although other uses have been found for the process andequipment as well. The important point in using the particular processand equipment is that the material being welded must be welded in ahydrogen or other inflammable gas in order to avoid oxidation of theparts being Welded. Heretofore an operator would hold the weldingelectrode from the bottom of the jar and Watch the work through the sideof the jar. Small molten particles fall from the article being weldedand work support during the welding operation and sometimes ignite theoxygen-hydrogen or other inflammable mixture that collects at the bottomof the jar which causes an explosion of that strata thus burning thehands of an operator unless they are properly covered. As a result, theoperator must wear gloves and this is a hindrance to careful welding andalso causes the hands to perspire. In operation of the welding process,hydrogen or other gas is introduced at the top of the jar and continually supplied in order to keep the jar completely filled with thedesired gas. The gas, of course, will flow from the bottom or lower endof the jar in a continuous stream.

It is an object of the invention among others to provide a protectingcover, Work support and light filter to carry out a welding process inan' atmosphere of hydrogen wherein the equipment for carrying out thewelding process is made safer for operation; to improve the conditionsunder which an operator works, to provide equipment that is simple andeconomical in construction and durable and long lasting in operation.

In carrying out the objects of the invention there is provided aprotecting cover that is placed over an article being welded wherein thewelding operation takes place in an atmosphere of hydrogen, a gas hereinreferred to by way of example only, comprising a bell shaped member withan opening in the top to enter hydrogen into the bell shaped member.There is also an opening in the side of the bell shaped member through iwhich a welding electrode is entered into the bell shaped member. Theelectrode is flexibly mounted and sealed with the bell shaped member.The bell shaped member is transparent and is open at the bottom. Theelectrode is flexibly mounted to the bell shaped member by a bellowsmember which has one end thereof attached to the side of the bell shapedmember and surrounds the opening while the other end of the bellows isattached to the welding electrode. A gasket seals the space between thebellows and electrode and allows movement of the electrode through thegasket without breaking the seal.

There is provided a work support to hold an article to be Welded whichwork support is adjustable vertically and over which the bell shapedmember is placed and supported by grasping the electrode. Connected tothe work support is a foldable screen which opens to contact the bellshaped member when the bell shaped member is in place over the worksupport to catch any particles of molten metal falling from the articlebeing Welded.

Also in combination with the work support and bell shaped member is alight shutter which is associated with the welding electrode and placedbetween the work support and an operator. The light shutter is arrangedto close and attenuate the light of the are just before the electricalswitch is closed which allows electric current to flow to the Weldingelectrode.

With the foregoing and other objects in View, the invention will be morefully described hereinafter and will be particularly pointed out in theclaims appended hereto.

In the drawings, wherein like symbols refer to like or correspondingparts throughout the several views:

Figure 1 is a perspective view showing the work support. bell shapedprotective cover, welding electrode and light filter in assembledrelation.

Figure 2 is a part sectional and part elevational view showing thewelding electrode passing through the bell shaped member with thebellows and seal to flexibly connect the welding electrode to the bellshaped member in section.

Figure 3 is a part sectional and part elevational view showing the bellshaped member over the work support with a screen member closing thespace between the two.

Referring to Figure l of the drawings, a protective cover is representedat l and is in the shape of a bell shaped member and is transparent. Thebell shaped protective cover I has been made of glass but may be made ofany other material design operation.

that is transparent and will stand the heat. At the top of the bellshaped member l is an opening 2 to which a tube 3 connects and hydrogengas may be delivered to the interior of the bell shaped member I throughtube 3 and opening 2. The bottom portion 4 of the bell shaped member lis left entirely open hence hydrogen from the interior of bell shapedmember i may flow out the open bottom portion 4 and a steady flow or"hydrogen maintained through the bell shaped member I at all times.

In the side wall 5 of the bell shaped member i (see Figure 2) there isan opening 6 through which a welding electrode 7' having a carbon ortungsten electrode or tip may extendinto the interior of the bell shapedmember 5. It is necessary to seal opening 6 in order to insure a purehydrogen atmosphere within the bell shaped member I and any sealed jointmust be'flexible so as to have freedom or movement of the weldingelectrode 7 within the bell shaped member 5.

The-side wall-5 of the bell shaped member 5 has a projecting portion 8around the opening 5 which receives one end of a bellows 9. The end ofthe bellows may be placed in the projection 8 when it 1 is' inmolten'state or any type of adhesive may be used to join the bellows tothe glass projection 8. At the other endof bellows 9 is a sealing memberI!) through which the weldingelectrode l passes.

"The sealing member Ill may be of any suitable material'rbutithematerialmust possess elasticity to' allow the welding electrode l to bemoved in and-out ofthe sealing member ill and up and downwithoutbreaking the seal. The welding electrodehas a handle -ll preferably ofBakelite 'which :an operator grasps to support both the weldingelectrode 1 and the bell shaped member l when a weldingoperationistaking place.

view-of a pivotal connection l5 with vertically extensible member it toallow'for angularly adjusting the article being welded. The verticallyextensible member lfihas connected thereto a foldabie screen ll-showncollapsed in dotted lines in .lF-"igure 3, and extended in full lines inFigure 3;.

The foldable screen is similar to an umbrella in .The screen is of smallmesh to catch small particles and the screen may be manipulated by handto fold or unfold into place.

In operation, anoperator grasps the. handle it on welding electrode 1and prepares to start the welding operation. An article to be welded isplaced on the head portion l3 and the bell shaped member l and weldingelectrode '1 are put into position over'the worksupport 2 with the foldable screen ll held up in the dotted line position of Figure 3 until thebellshaped member l is in place after which the screen IT is allowed todrop intothe. full line position of Figure 3. In the full line positionof Figure 3 the screen ll contacts the bell shaped member I thus closingthe space between the bellmshaped memberl and the work support l2 andserves to collect any molten metal falling from the article being weldedand reduces the explosion and fire hazard hence allowing an operator towork without gloves. When the bell shaped member I and welding rod '1are in place,

of the operator during the welding operation.

During the summer it is particularly annoying for an operator to weargoggles, hence the present shutter arrangement makes it possible for theoperator to work without the use of goggles. The shutter is open whenthe current to the welding electrode is off and when the shutter isclosed,

electric current flows to the welding electrode 1. The shutter 98 iscontrolled by a foot pedal 2! which pedal 2! when pressed down closesstrips 25], Pressing-down of pedal 2! also actuates an electric switchto close the switch and allows electric current to pass weldingelectrode 7.

While the invention has been described in connection with-severalspecific embodiments, it is to be understood that the words whichhavebeen used are words of description rather than limitation, and thatpractice-of the invention Within the scope of the appended claims mayberesorted to without departing from the true scope of the invention inall its aspects.

I claim:

1. A welding apparatus for performing a welding operation :on aworkpiece in an atmosphere of inflammable gas comprising a container'forconfining an inflammable gas around a work piece, said container havingan opening at the top for introducing said inflammable gas into saidcontainer and an opening at the bottom for permitting the workpieceto-be inserted within the containertan'd for permitting the gas toexhaust from thecontainena porous shield positioned between said workpiece and said bottom opening to prevent incandescent pieces of metalfrom falling through the opening while permitting said gas to passthrough the shield.

2. An apparatus according to claim 1 wherein a work supportiispositioned through said bottom opening to .support said work piece insaid container and to support said shield.

3. An apparatus according to claim 2 wherein said shield is flexiblymounted .on said support.

4. An apparatus accordingto claim 3 wherein said shield is of anumbrella shape flexibly mounted at the center to said work support andin the open position extending to the inside surface of said container.

THOMAS W. GRIFFITHS.

REFERENCES CITED The following references are of record in the or thispatent:

UNITED STATES PATENTS Number Name Date 975,845 Farkas Mar. 15, 19101,093,197 Morrison Apr. 14, 1914 1,354,266 Plant Sept. 28, 19201,616,145 Shipman Feb. 1, 1927 2,336,283 Neill Dec. 7, 1943 2,373,041Martindell Apr. 3, 1945

